Planar-type and fin-type semiconductor devices have been studied in order to miniaturize semiconductor devices each including a substrate, such as a silicon substrate. Such semiconductor devices mostly utilize reduction of the short channel effect by using source/drain extension regions (hereinafter simply referred to as extension regions). In order to reduce the short channel effect, shallow extension regions need to be formed, and a high concentration of an impurity needs to be implanted into the extension regions.
For this reason, a technique called plasma doping in which silicon, etc., is doped with an impurity by using plasma started to be developed in the late 1980s (see NON-PATENT DOCUMENT 1). Research and development have been directed at forming shallow extension regions of high impurity concentration using plasma doping since the late 1990s (see NON-PATENT DOCUMENTS 2 and 3).